Why Sleeping On Decisions Can Lead to Better Decision-making

Our Brain Works on the Decision Whilst We Sleep

When there is an important decision that we have to make we are often told to ‘sleep on it’ and then decide the next day. And in fact often it is much easier to make the decision after having slept on it. From a brain science perspective there seems to be more to this idea than we might think.

Sid Kouider from Laboratoire de Sciences Cognitives et Psycholinguistique in Paris and his colleagues found that human brains make decisions during sleep. Participants in their study had to make simple decisions: one group had to decide whether spoken words were animals or objects, another group had to decide whether spoken words were real words or pseudo-words, and then they had to press a button either with their left or with their right hand. During the experiment they were allowed to nod off and their brain activity was recorded. After falling asleep of course participants stopped pushing the buttons. However, the related brain activity continued. So the brain was still responding and preparing the motor response, only that this response was not executed as it had been while participants had still been awake. However, after waking up, participants did not remember having heard the words while they had been asleep. Thus, our brain perceives what is going on around it while we are sleeping and prepares decisions, even if we are not conscious about it.

Thus, while sleeping on a decision your brain is likely to prepare this very decision. Therefore is seems to be good advice to do this!

About the Author

Dr Katharina Lochner is the former research director for the cut-e Group which was acquired by Aon in 2017. Katharina is now a researcher and lecturer at the University of Applied Sciences Europe in Iserlohn, Germany. In her role at cut-e, she applied the research in organizational and work psychology to real-world assessment practice. She has a strong expertise in the construction and evaluation of online psychometric tools.